Single gate heterostructure dopingless TFET: a comprehensive sensitivity investigation with exposure to various chemical analytes

Abstract

This study proposes a new chemical sensor designed using a single gate heterostructure dopingless tunnel field effect transistor (SG-HS-DLT). Combining Si_0.6Ge_0.4 in the source and HfO₂ as the gate dielectric improves the sensor’s drain current sensitivity. Many chemical analytes, including hexane (C₆H₁₄), methanol (CH₃OH), isopropanol (Iso-C₃H₇OH), dichloromethane (CH₂Cl₂), and chloroform (CHCl₃) have been considered during the investigation. The conducting polymer is used as the gate metal due to its compatibility with the electronic chemical sensor. Modifying the gate work function with exposure to chemical substances is employed to determine the sensitivity of the reported chemical sensor. The electrical performance of the sensor is examined using transfer characteristics, switching ratio, average SS, BTBT rate, threshold voltage, electron concentration, energy band, and potential. Correspondingly, the sensitivity investigation comprises drain current sensitivity (S_Drain), current ratio sensitivity (S_R), average SS sensitivity (S_AvgSS), and threshold voltage sensitivity (S_VT). Further, the sensitivity analysis is extended for various temperatures and mole fractions (x). The SG-HS-DLT chemical sensor displays a higher value of S_Drain of 3.64 × 10⁵, S_Avg.SS of 0.69444 for CHCl₃ at room temperature. This article extensively uses the Silvaco TCAD simulation software to investigate the proposed chemical sensor.